I explore physics implications of the External Reality Hypothesis (ERH) that there exists an external physical reality completely independent of us humans. I argue that with a sufficiently broad definition of mathematics, it implies the Mathematical Universe Hypothesis (MUH) that our physical world is an abstract mathematical structure. I discuss various implications of the ERH and MUH, ranging from standard physics topics like symmetries, irreducible representations, units, free parameters, randomness and initial conditions to broader issues like consciousness, parallel universes and (...) Gödel incompleteness. I hypothesize that only computable and decidable (in Gödel’s sense) structures exist, which alleviates the cosmological measure problem and may help explain why our physical laws appear so simple. I also comment on the intimate relation between mathematical structures, computations, simulations and physical systems. (shrink)

How all philosophical explanations of human consciousness and the fundamental structure of the cosmos are bizarre—and why that’s a good thing Do we live inside a simulated reality or a pocket universe embedded in a larger structure about which we know virtually nothing? Is consciousness a purely physical matter, or might it require something extra, something nonphysical? According to the philosopher Eric Schwitzgebel, it’s hard to say. In The Weirdness of the World, Schwitzgebel argues that the answers to these fundamental (...) questions lie beyond our powers of comprehension. We can be certain only that the truth—whatever it is—is weird. Philosophy, he proposes, can aim to open—to reveal possibilities we had not previously appreciated—or to close, to narrow down to the one correct theory of the phenomenon in question. Schwitzgebel argues for a philosophy that opens. According to Schwitzgebel’s “Universal Bizarreness” thesis, every possible theory of the relation of mind and cosmos defies common sense. According to his complementary “Universal Dubiety” thesis, no general theory of the relationship between mind and cosmos compels rational belief. Might the United States be a conscious organism—a conscious group mind with approximately the intelligence of a rabbit? Might virtually every action we perform cause virtually every possible type of future event, echoing down through the infinite future of an infinite universe? What, if anything, is it like to be a garden snail? Schwitzgebel makes a persuasive case for the thrill of considering the most bizarre philosophical possibilities. (shrink)

زبان دین خواهان کشف و تببین ماهیت زبانی است که در الفاظ و گزاره‌های دینی به کار رفته است. این کشف به ما کمک می‌کند تا مراد اصلی یا فحوای حقیقی مضامین دینی را که در قالب زبان بشری بیان شده است دریابیم. غزالی، متأثر از نگرش‌های کلامی و یافته‌های عرفانی خود و با لحاظ مراتب مختلف ادراک مردمان، دیدگاه‌های متفاوتی را در این موضوع ابراز داشته است. از این رو، گاه اجتناب از تأویل را لازم می‌داند، گاه ضرورت عدول (...) از معنای ظاهر را خاطرنشان می‌سازد و گاه با بحث از «روح معنا» که خود طراح آن است، بدون آن که معنای ظاهر انکار شود، گوهر حقیقی معنا را فارغ از ویژگی‌های مصادیق آن منظور می‌نماید. در عین حال، جریان اندیشۀ او در این باب به منزل اشتراک لفظی نیز ورود می‌کند و پایان سیر آن در معناشناسی اوصاف‌ الهی چنین است که حقیقتش نصیب فهم هیچ کس نخواهد شد و معانی آن در صید هیچ ادراکی درنخواهد آمد. (shrink)

It is no exaggeration to say that there has been an explosion of activity in the field of philosophical enquiry that is known as natural theology. Having been smothered in the early part of the twentieth century due to the dominance of the anti-metaphysical doctrine of logical positivism, natural theology began to make a comeback in the late 1950s as logical positivism collapsed and analytic philosophers took a newfound interest in metaphysical topics such as possibility and necessity, causation, time, the (...) mind-body problem, and God. This chapter begins by considering how we might characterise natural theology as a field of enquiry. It then proceeds to survey the landscape of contemporary natural theology, which has spawned a large and at times highly technical body of literature. Finally, consideration is given to two epistemological issues confronting the theist who wishes to appeal to natural theology, which could be termed the problem of the gap(s) and the problem of accessibility. (shrink)

I present a proof of the quantum probability rule from decision-theoretic assumptions, in the context of the Everett interpretation. The basic ideas behind the proof are those presented in Deutsch's recent proof of the probability rule, but the proof is simpler and proceeds from weaker decision-theoretic assumptions. This makes it easier to discuss the conceptual ideas involved in the proof, and to show that they are defensible.

Evidence for instances of astrophysical 'fine tuning' (or 'coincidences') is thought by some to lend support to the design argument (i.e. the argument that our universe has been designed by some deity). We assess some of the relevant empirical and conceptual issues. We argue that astrophysical fine tuning calls for some explanation, but this explanation need not appeal to the design argument. A clear and strict separation of the issue of anthropic fine tuning on one hand and any form of (...) Eddingtonian numerology and teleology on the other, may help clarify arguably the most significant issue in the philosophy of cosmology. (shrink)

Evidence for instances of astrophysical ‘fine tuning’ (or ‘coincidences’) is thought by some to lend support to the design argument (i.e. the argument that our universe has been designed by some deity). We assess some of the relevant empirical and conceptual issues. We argue that astrophysical fine tuning calls for some explanation, but this explanation need not appeal to the design argument. A clear and strict separation of the issue of anthropic fine tuning on one hand and any form of (...) Eddingtonian numerology and teleology on the other, may help clarify arguably the most significant issue in the philosophy of cosmology. (shrink)

Crane envisions the speculative conjecture that intelligent civilizations might want and be able to produce black holes in the very far future. He implicitly suggests two main purposes of this enterprise: (i) energy production and (ii) universe production. We discuss those two options. The commentary is obviously highly speculative and should be read accordingly.

In this philosophical paper, we explore computational and biological analogies to address the fine-tuning problem in cosmology. We first clarify what it means for physical constants or initial conditions to be fine-tuned. We review important distinctions such as the dimensionless and dimensional physical constants, and the classification of constants proposed by Lévy-Leblond. Then we explore how two great analogies, computational and biological, can give new insights into our problem. This paper includes a preliminary study to examine the two analogies. Importantly, (...) analogies are both useful and fundamental cognitive tools, but can also be misused or misinterpreted. The idea that our universe might be modelled as a computational entity is analysed, and we discuss the distinction between physical laws and initial conditions using algorithmic information theory. Smolin introduced the theory of "cosmological natural selection" with a biological analogy in mind. We examine an extension of. (shrink)

Inflationary cosmology has been widely accepted due to its successful predictions: for a “generic” initial state, inflation produces a homogeneous, flat, bubble with an appropriate spectrum of density perturbations. However, the discovery that inflation is “generically eternal,” leading to a vast multiverse of inflationary bubbles with different low-energy physics, threatens to undermine this account. There is a “predictability crisis” in eternal inflation, because extracting predictions apparently requires a well-defined measure over the multiverse. This has led to discussions of anthropic predictions (...) based on a measure over the multiverse, and an assumption that we are typical observers. I will give a pessimistic assessment of attempts to make predictions in this sense, emphasizing in particular problems that arise even if a unique measure can be found. (shrink)

The aim of this paper is to present some philosophical considerations about the supposed AI emergence in the future. However, the predicted timeline of this process is uncertain. To avoid any kind of speculations on the proposed analysis from a scientific point of view, a metaphysical approach is undertaken as a modal context of the discussion. I argue that modal claim about possible AI emergence at a certain point of time in the future is justified from a temporal perspective. Therefore, (...) worldwide society must be prepared for possible AI emergence and the expected profound impact of such an event on the existential status of humanity. (shrink)

A longstanding issue in attempts to understand the Everett (Many-Worlds) approach to quantum mechanics is the origin of the Born rule: why is the probability given by the square of the amplitude? Following Vaidman, we note that observers are in a position of self-locating uncertainty during the period between the branches of the wave function splitting via decoherence and the observer registering the outcome of the measurement. In this period it is tempting to regard each branch as equiprobable, but we (...) argue that the temptation should be resisted. Applying lessons from this analysis, we demonstrate (using methods similar to those of Zurek's envariance-based derivation) that the Born rule is the uniquely rational way of apportioning credence in Everettian quantum mechanics. In doing so, we rely on a single key principle: changes purely to the environment do not affect the probabilities one ought to assign to measurement outcomes in a local subsystem. We arrive at a method for assigning probabilities in cases that involve both classical and quantum self-locating uncertainty. This method provides unique answers to quantum Sleeping Beauty problems, as well as a well-defined procedure for calculating probabilities in quantum cosmological multiverses with multiple similar observers. (shrink)

I defend a how-possibly argument for Kantian (or Kant*-ian) transcendental idealism, drawing on concepts from David Chalmers, Nick Bostrom, and the cyberpunk subgenre of science fiction. If we are artificial intelligences living in a virtual reality instantiated on a giant computer, then the fundamental structure of reality might be very different than we suppose. Indeed, since computation does not require spatial properties, spatiality might not be a feature of things as they are in themselves but instead only the way that (...) things necessarily appear to us. It might seem unlikely that we are living in a virtual reality instantiated on a non-spatial computer. However, understanding this possibility can help us appreciate the merits of transcendental idealism in general, as well as transcendental idealism’s underappreciated skeptical consequences. (shrink)

How should rational beliefs change over time? The standard Bayesian answer is: by conditionalization (a.k.a. Bayes’ Rule). But conditionalization is not an adequate rule for updating beliefs in “centred” propositions whose truth-value may itself change over time. In response, some have suggested that the objects of belief must be uncentred; others have suggested that beliefs in centred propositions are not subject to diachronic norms. Iargue that these views do not offer a satisfactory account of self-locating beliefs and their dynamics. A (...) third response is to replace conditionalization by a new norm that can deal with centred propositions. I critically survey anumber of new norms that have been proposed, and defend one particular approach. (shrink)

Do we think in a language-like format? Taking the marker of language-like formats to be the property of unconstrained systematicity, this paper considers the following master argument for the claim that we do: language is unconstrainedly systematic, if language is unconstrainedly systematic then so is thought, so thought is unconstrainedly systematic. It is easy to feel that there is something right about this argument, that there will be some way of filling in its details that will vindicate the idea that (...) our thought must be unconstrainedly systematic given that the language in which we express it is. Clearly, however, the second premise needs support—we need a principled reason for moving from the unconstrained systematicity of language to the unconstrained systematicity of thought. This paper gives three passes at formulating such a principle. This turns out to be much harder than it might seem. We should, I conclude, resist falling too easily for the lure of this master argument for the language-like format of thought. (shrink)

This article proposes revisions to the Laws of Cricket and to the criminal law of England. The Laws of Cricket should be revised so that an umpire may give a batsman out without having to specify precisely how he got out. The criminal law should be revised so that (e.g.) aiding and abetting a murderer is not subsumed under the crime of murder.

Currently, the most popular views about how to update de se or self-locating beliefs entail the one-third solution to the Sleeping Beauty problem.2 Another widely held view is that an agent‘s credences should be countably additive.3 In what follows, I will argue that there is a deep tension between these two positions. For the assumptions that underlie the one-third solution to the Sleeping Beauty problem entail a more general principle, which I call the Generalized Thirder Principle, and there are situations (...) in which the latter principle and the principle of Countable Additivity cannot be jointly satisfied. The most plausible response to this tension, I argue, is to accept both of these principles, and to maintain that when an agent cannot satisfy them both, she is faced with a rational dilemma. (shrink)

Time Travel: Probability and Impossibility By EffinghamNikkOxford University Press, 2020. 256 pp.

Philosophers of science have often favoured reductive approaches to how-possibly explanation. This article identifies three alternative conceptions making how-possibly explanation an interesting phenomenon in its own right. The first variety approaches “how possibly X?” by showing that X is not epistemically impossible. This can sometimes be achieved by removing misunderstandings concerning the implications of one’s current belief system but involves characteristically a modification of this belief system so that acceptance of X does not result in contradiction. The second variety offers (...) a potential how-explanation of X. It is usually followed by a range of further potential how-explanations of the same phenomenon. In recent literature the factual claims implied by the second variety have been downplayed whereas the heuristic role of mapping the space of conceptual possibilities has been emphasized. I will focus especially on this truth-bracketing sense of potentiality when looking closer at the second variety in the paper. The third variety has attracted less interest. It presents a partial how-explanation of X. Typically it aims to establish the existence of a mechanism by which X could be and was generated. The third conception stands out as the natural alternative for the advocate of ontic how-possibly explanations. This article transfers Salmon’s view that explanation-concepts can be broadly divided into epistemic, modal, and ontic to the context of how-possibly explanations. Moreover, it is argued that each of the three above-mentioned varieties of how-possibly explanation occurs in science. To recognize this may be especially relevant for philosophers. We are often misled by the promises of various why-explanation accounts, and seem to have forgotten nearly everything about the diversity of how-possibly explanations. (shrink)

By the end of the twentieth century, many prominent cosmologists were fascinated by the questions why is the universe the way it is, and why does the universe appear to be just right for life to emerge.1 Indeed, the shift to posing questions beginning with why rather than what or how is a relatively recent development in modern cosmology. This paper begins by looking at the emergence of why questions in cosmological discourse by tracing affiliated anthropic reasoning and fine-tuning arguments (...) in cosmology. I also consider recent suggestions that the laws of physics may themselves evolve. In response to the why questions, this paper then examines the proliferation of multiverse discourse in the late twentieth... (shrink)

Bayesian probabilistic explication of inductive inference conflates neutrality of supporting evidence for some hypothesis H (“not supporting H”) with disfavoring evidence (“supporting not-H”). This expressive inadequacy leads to spurious results that are artifacts of a poor choice of inductive logic. I illustrate how such artifacts have arisen in simple inductive inferences in cosmology. In the inductive disjunctive fallacy, neutral support for many possibilities is spuriously converted into strong support for their disjunction. The Bayesian “doomsday argument” is shown to rely entirely (...) on a similar artifact, for the result disappears in a reanalysis that employs fragments of inductive logic able to represent evidential neutrality. Finally, the mere supposition of a multiverse is not yet enough to warrant the introduction of probabilities without some factual analog of a randomizer over the multiverses. (shrink)

Gott (Nature 363:315–319, 1993) considers the problem of obtaining a probabilistic prediction for the duration of a process, given the observation that the process is currently underway and began a time t ago. He uses a temporal Copernican principle according to which the observation time can be treated as a random variable with uniform probability density. A simple rule follows: with a 95% probability.

The Doomsday Argument and the Simulation Argument share certain structural features, and hence are often discussed together. Both are cases where reflecting on one’s location among a set of possibilities yields a counter-intuitive conclusion—in the first case that the end of humankind is closer than you initially thought, and in the second case that it is more likely than you initially thought that you are living in a computer simulation. Indeed, the two arguments do have some structural similarities. But there (...) are also significant disanalogies between the two arguments, and I argue that these disanalogies mean that the Simulation Argument succeeds and the Doomsday Argument fails. (shrink)

(No abstract is available for this citation).

Most philosophers accept some version of the requirement of total evidence (RTE), which tells us to always update on our complete evidence, which often includes ‘background information’ about how that evidence was collected. But different philosophers disagree about how to implement that requirement. In this article, I argue against one natural picture of how to implement the RTE in likelihood arguments, and I argue in favor of a different picture. I also apply my picture to the controversy over the so-called (...) ‘Objection from Anthropic Bias’ to the fine-tuning argument, and argue that the Objection from Anthropic Bias fails. (shrink)

Recent developments in cosmology indicate that every history having a non-zero probability is realized in infinitely many distinct regions of spacetime. Thus, it appears that the universe contains infinitely many civilizations exactly like our own, as well as infinitely many civilizations that differ from our own in any way permitted by physical laws. We explore the implications of this conclusion for ethical theory and for the doomsday argument. In the infinite universe, we find that the doomsday argument applies only to (...) effects which change the average lifetime of all civilizations, and not those which affect our civilization alone. (shrink)

I argue that a popular view about self-locating evidence implies that there are cases in which agents have surprisingly strong evidence for their own reincarnation. The central case is an ‘Immortal Beauty' scenario, modelled after the well-known Sleeping Beauty puzzle. I argue that if the popular ‘thirder’ solution to the puzzle is correct, then Immortal Beauty should be confident that she's going to be reincarnated. The essay also examines another pro-reincarnation argument due to Michael Huemer (2021). I argue that his (...) argument fails, and that my argument establishes an alternative way in which mere existence can be evidence for reincarnation. I then examine whether my result generalizes. (shrink)

The experimental setup of the self-referential quantum measurement, jovially known as the ‘quantum suicide’ or the ‘quantum Russian roulette’ is analyzed from the point of view of the Principal Principle of David Lewis. It is shown that the apparent violation of this principle – relating objective probabilities and subjective chance – in this type of thought experiment is just an illusion due to the usage of some terms and concepts ill-defined in the quantum context. We conclude that even in the (...) case that Everett’s (or some other ‘no-collapse’) theory is a correct description of reality, we can coherently believe in equating subjective credence with objective chance in quantum-mechanical experiments. This is in agreement with results of the research on personal identity in the quantum context by Parfit and Tappenden. (shrink)

The answer to the fine-tuning problem of the universe has been traditionally sought in terms of either design or multiverse. In philosophy circles, this is sometimes expanded by adding the option of explanatory nihilism—the claim that there is no explanation for statements of that high level of generality: fine-tunings are brute facts. In this paper, we consider the fourth option which, at least in principle, is available to us: co-evolution of the universe and observers. Although conceptual roots of this approach (...) could be found already in ancient stoicism, it is still the least investigated explanatory option for resolving the problem of empirical fine tunings. We offer two preliminary models along which the co-evolution hypothesis could be developed further. They are still on the level of speculative metaphysics, but there are opportunities along the way to generate predictions which are in principle testable, especially in the domain of large-scale numerical simulations. (shrink)

The judgment that a given event is epistemically improbable is necessary but insufficient for us to conclude that the event is surprising. Paul Horwich has argued that surprising events are, in addition, more probable given alternative background assumptions that are not themselves extremely improbable. I argue that Horwich’s definition fails to capture important features of surprises and offer an alternative definition that accords better with intuition. An important application of Horwich’s analysis has arisen in discussions of fine-tuning arguments. In the (...) second part of the paper I consider the implications for this argument of employing my definition of surprise. I argue that advocates of fine-tuning arguments are not justified in attaching significance to the fact that we are surprised by examples of fine-tuning. (shrink)

We discuss a number of fundamental aspects of modern cosmological concepts, from the phenomenological, observational, theoretical and epistemic points of view. We argue that the modern cosmology, despite a great advent, in particular in the observational sector, is yet to solve important problems, posed already by the classical times. In particular the stress is put on discerning the scientific features of modern cosmological paradigms from the more speculative ones, with the latter immersed in some aspects deeply into mythological world picture. (...) We finally discuss the principal paradigms, which are present in the modern cosmological studies and evaluate their epistemic merits. (shrink)

Does the claimed fine-tuning of the constants of nature for life give reason to think that there are many other universes in which the constants have different values? Or does the inference from fine-tuning to a multiverse commit what Hacking calls the inverse gambler’s fallacy? The present paper considers two fine-tuning problems that seem promising to consider because they are in many respects analogous to the problem of the fine-tuned constants. Reasoning that parallels the inference from fine-tuning to a multiverse (...) seems prima facie adequate in these problems. However, it turns out that in both cases there are independent empirical reasons to believe the hypotheses that are analogous to the multiverse hypothesis. In the absence of such evidence, it would be coherent to raise the inverse gambler’s fallacy charge against the inference from fine-tuning to these multiverse-type hypotheses. In response to this finding, I suggest taking the possibility seriously that established standards of rationality may not allow us to decide whether the inference from fine-tuning to a multiverse is fallacious or not. The paper concludes by sceptically assessing the prospects for obtaining independent empirical evidence for concrete multiverse theories. (shrink)

Philosophers defend, and often believe, controversial philosophical claims. Since they aren’t clueless, they are usually aware that their views are controversial—on some occasions, the views are definitely in the minority amongst the relevant specialist-experts. In addition, most philosophers are aware that they are not God’s gift to philosophy, since they admit their ability to track truth in philosophy is not extraordinary compared to that of other philosophers. In this paper I argue that in many real-life cases, such beliefs in controversial (...) claims are irrational. This means that most philosophers have irrational philosophical beliefs. (shrink)

According to the Fine-Tuning Argument, the existence of life in our universe confirms the Multiverse Hypothesis. A standard objection to FTA is that it violates the Requirement of Total Evidence. I argue that RTE should be rejected in favor of the Predesignation Requirement, according to which, in assessing the outcome of a probabilistic process, we should only use evidence characterizable in a manner available before observing the outcome. This produces the right verdicts in some simple cases in which RTE leads (...) us astray, and, when applied to FTA, it shows that our evidence does confirm HM. (shrink)

David Builes presents a paradox concerning how confident you should be that any given member of an infinite collection of fair coins landed heads, conditional on the information that they were all flipped and only finitely many of them landed heads. We argue that if you should have any conditional credence at all, it should be 1/2.

In the context of the Sleeping Beauty problem, it has been argued that so-called “halfers” can avoid Dutch book arguments by adopting evidential decision theory. I introduce a Dutch book for a variant of the Sleeping Beauty problem and argue that evidential decision theorists fall prey to it, whether they are halfers or thirders. The argument crucially requires that an action can provide evidence for what the agent would do not only at other decision points where she has exactly the (...) same information, but also at decision points where she has different but “symmetric” information. (shrink)

Arendt’s theoretical influence is generally traced to Heidegger and experientially to the traumatic events that occurred in Europe during the Second World War. Here, we suggest that Arendt’s conception of politics may be usefully enriched via a proto-anthropic principle found in Augustine and adopted by Arendt throughout her writings. By appealing to this anthropic principle; that without a spectator there could be no world; a profound connection is made between the ‘cosmic jackpot’ of life in the universe and the uniquely (...) human activity that takes place in the political realm. By making this connection we suggest that solutions present themselves to a central puzzle arising in Arendt’s thought: namely, what it is that people actually do in the political realm. The first solution directly addresses the issue of content: what people talk about in Arendt’s public space. The second addresses the importance of ‘maintaining’ a space of appearances. The third considers the effect of participating in and observing the public domain. Consequently, we conclude that, for Arendt, action is nothing less than the activity of ‘world-making.’. (shrink)

The answer to the fine-tuning problem of the universe has been traditionally sought in terms of either design or multiverse. In philosophy circles, this is sometimes expanded by adding the option of explanatory nihilism – the claim that there is no explanation for statements of that high level of generality: fine-tunings are brute facts. In this paper, we consider the fourth option which, at least in principle, is available to us: co-evolution of the universe and obsevers. Although conceptual roots of (...) this approach could be found already in ancient stoicism, it is still the least investigated explanatory option for resolving the problem of empirical fine tunings. We offer two preliminary models along which the co-evolution hypothesis could be developed further. They are still on the level of speculative metaphysics, but there are opportunities along the way to generate predictions which are in principle testable, especially in the domain of large-scale numerical simulations. (shrink)

We have demonstrated, using the Cantor dust method, that the statistical distribution of appearance and disappearance of rodents species (Arvicolid rodent radiation in Europe) follows power laws strengthening the evidence for a fractal structure set. Self-similar laws have been used as model for the description of a huge number of biological systems. With Nottale we have shown that log-periodic behaviors of acceleration or deceleration can be applied to branching macroevolution, to the time sequences of major evolutionary leaps (global life tree, (...) sauropod and theropod dinosaurs postural structures, North American fossil equids, rodents, primates and echinoderms clades and human ontogeny). The Scale-Relativity Theory has others biological applications from linear with fractal behavior to non-linear and from classical mechanics to quantum mechanics. (shrink)

In this paper, I argue that some plausible principles concerning which credences are rationally permissible for agents given information about one another’s epistemic and credal states have some surprising consequences for which credences an agent ought to have in light of self-locating information. I provide a framework that allows us to state these constraints and draw out these consequences precisely. I then consider and assess the prospects for rejecting these prima facie plausible principles.

The Doomsday Argument says we should increase our subjective probability that Doomsday will occur once we take into account how many humans have lived before us. One objection to this conclusion is that we should accept the Self-Indication Assumption (SIA): Given the fact that you exist, you should (other things equal) favor hypotheses according to which many observers exist over hypotheses on which few observers exist. Nick Bostrom argues that we should not accept the SIA, because it can be used (...) without knowledge of birth rank. Bradley Monton tries to construct a Doomsday Argument without knowledge of birth rank. I argue that Monton fails. The argument he constructs has implicit knowledge of birth rank and it is this knowledge that does the work. Furthermore, I argue that provided we dont have certain specific information about the future, the Doomsday Argument requires knowledge of birth rank. (shrink)

We give an analysis of the Monty Hall problem purely in terms of confirmation, without making any lottery assumptions about priors. Along the way, we show the Monty Hall problem is structurally identical to the Doomsday Argument.

This article defends the Doomsday Argument, the Halfer Position in Sleeping Beauty, the Fine-Tuning Argument, and the applicability of Bayesian confirmation theory to the Everett interpretation of quantum mechanics. It will argue that all four problems have the same structure, and it gives a unified treatment that uses simple models of the cases and no controversial assumptions about confirmation or self-locating evidence. The article will argue that the troublesome feature of all these cases is not self-location but selection effects.